Roller chain is a type of chain drive designed for the transfer of mechanical power in many kinds of domestic, industrial and agricultural machinery, including conveyors, wire and tube drawing machines, printing presses, cars, motorcycles, and simple machines like bicycles. Commonly, a roller chain has a series of links designed to mesh with the teeth of the sprockets of the machine, and are flexible in only one dimension. Each link may include short cylindrical rollers held together by side links by an axle that is connected to the side links and passes through the rollers. The chain is commonly driven by a toothed wheel called a sprocket. It is a simple, reliable, and efficient means of power transmission. Generally, there are two types of links alternating in the roller chain. The first type is inner links, having two inner plates held together by two axles upon which two rollers may rotate. Inner links alternate with the second type, the outer links, consisting of two outer plates held together by pins passing through the bushings of the inner links. Roller chain with plastic rollers has been used in the food, beverage, pharmaceutical, packaging, power transmission and related product processing industries. However, it is common knowledge that the rollers wear out faster than the plates or side bars. As a result, a chain that would have considerable life remaining must be discarded because some of the rollers are out of specification. This of course is an expensive and time consuming process. Conventional solutions require disassembly of the chain to even attempt a repair that may irreparably damage the chain. Moreover, conventional plastic rollers are either machined or molded in one piece that is permanently assembled into the roller chain. Since the roller is permanently assembled into the chain, a worn roller cannot be removed and replaced without destroying the interference fit between the side bars and the axle (for carrier and top rollers) or destroying the integrity of a retainer (for outboard rollers).
Therefore, there is a need in the art for a repair roller that overcomes the aforementioned disadvantages and provides extended life for the chain and lower costs.